کاربرد شاخص های ژئومورفومتریک در تعیین کمیت ژئودایورسیتی مناطق کوهستانی، مطالعه موردی: کوهستان میشوداغی، شمال غرب ایران (مقاله علمی وزارت علوم)
درجه علمی: نشریه علمی (وزارت علوم)
آرشیو
چکیده
ارزیابی ژئودایورسیتی یکی از مراحل اولیه و اصلی در توسعه اقدامات حفاظت از زمین است. هدف اصلی پژوهش حاضر، ارزیابی کمی تنوع زمینی توده کوهستانی است که از شدت نمایان بودن مورد اغفال است. این پژوهش، یک روش استانداردشده احتمالی پیشنهاد می کند که از طریق جمع مقادیر عناصر تراکم آبراهه، فرکانس جریان، برجستگی ارتفاع، شدت فرسایش، گرادیان شیب، رطوبت توپوگرافی، شیب طولی رودخانه، نسبت مساحت سطح، فراوانی ناهمواری و لیتولوژی محاسبه می شود. نتایج نشان دهنده آن بود که تنوع تراکم آبراهه در دامنه ها بیشتر است. مقادیر زیاد تنوع در عامل زمین شناسی مربوط به بستر زمین شناسی مقاوم در برابر فرسایش است. زاویه شیب بیشتر تنوع بیشتری را در منطقه ایجاد می کند. مقدار زیاد شاخص شدت فرسایش موجبات شکل گیری تنوع بیشتری را در منطقه فراهم کرده است. مقدار زیاد فرکانس جریان >5 در منطقه موجبات تنوع بیشتری در منطقه شده است. مقادیر زیادتر شاخص فراوانی ناهمواری به طور دقیق بر مناطقی منطبق است که تغییر شکل چشمگیری دارند و نشان دهنده تنوع بیشتری است. بیشترین مقدار شاخص رطوبت توپوگرافی 8/20 و در مناطق دشتی است. مقادیر نزدیک به 00/0 یا 00/1 برجستگی ارتفاع هر دو توپوگرافی زیر افقی را نشان می دهند که مقدار نزدیک تر 00/1 نشان دهنده تنوع بیشتری در منطقه است. مقادیر زیاد نسبت مساحت سطح، حاکی از یک منطقه ناهموار با تنوع زیاد است. بخش هایی تنوع بیشتری دارند که مقادیر شاخص شیب طولی رودخانه بیشتری به خود اختصاص داده اند. در کل، حد فاصل گسل شمالی و جنوبی کوهستان بیشترین تنوع را در اطراف خود ایجاد کرده است. روش ارائه شده ابزاری بالقوه و مؤثر برای حمایت از فرایندهای تصمیم گیری درباره مدیریت و حفاظت از ژئودایورسیتی در مقیاس های مختلف با کاربردهای احتمالی بیشتر در ایران است.The Use of Geomorphometric Indices for Quantifying the Geodiversity of Mountainous Areas (Case study: Mishu Mountain, Northwestern Iran)
Geodiversity assessment is one of the first and main steps in the development of land conservation measures. The main goal of the present study was to quantitatively evaluate the geodiversity of a mountain mass, which was neglected due to its visibility. This research proposed a possible standardized method of calculation through the sum of the elements of Surface Area/Raitio (SAR), Dissection Index (DI), Elevation relief (Er), Slope gradient (Sg), Amplitude of relief (Ar), Stream Length (SL), Drainage density (Dd), Stream frequency (fu), Topographic wetness Index (TwI), and lithology. In general, the distance between the northern and southern faults of the studied mountain had created the most diversity around it. The presented method can be a potentially effective tool for supporting decision-making processes regarding management and protection of geodiversity at different scales with possible applications in Iran.Keywords: Geomorphometric Indices, Geodiversity Quantity, Mishu Mountain, Northwestern IranIntroductionMountainous regions are characterized by spatial geomorphic heterogeneity, which gives significant geodiversity to the environment. Geodiversity assessment is one of the first and main steps in the development of land conservation measures. Geodiversity studies can be a valuable tool in ecosystem management and ecosystem service delivery, including sustainable geotourism. In recent decades, many researchers have turned their attention to the definition of geodiversity and its relationship to biodiversity, natural environment protection, ecosystem services, and geotourism. This research tried to use and measure some indicators to measure geomorphological diversity in Mishu mountain region. The Mishu Mountains contain a variety of geomorphological phenomena. The mountain area is less popular today among different regions due to habitat destruction and species extinction. In the past, it was one of the most valuable regions in the country in the regional network and was considered as an irreplaceable region. Due to the recent droughts, lack of codified management plans, and lack of attention to control and supervise miners as one of the main conflicts in the Mishu Mountains, we can point to the imbalance between livestock and rangeland. This area has witnessed many destructions over the past years. Mainly, geodiversity of Misho Mountain region has been involved in its development, providing both opportunities and constraints that need to be managed and understood. With the advent of new approaches to geodiversity, geographical spaces, such as Mount. Misho can be used effectively. Materials & MethodsIn this research, the methods of Benito-Calvo et al. (2009) and Melelli et al. (2017) were used with some special changes. Moreover, a possible standardized method was proposed through the sum of the values of the elements of Surface Area/Raitio (ASR), Dissection Index (DI), Elevation relief (Er), Slope gradient (Sg). Amplitude of relief (Ar), Stream Length (SL), Drainage density (Dd), Stream frequency (fu), Topographic wetness Index (TwI), and lithology. In this article, the quantitative index of GMI was estimated with 9 geomorphometric indices derived from digital elevation models in GIS environment. In addition, the lithology index was extracted from the geological map (Eq. 1).GmI = SARv + DIv + ERv + SGv + Arv + SLv+ Ddv+ Fuv+ TWIv+ GeovIt is necessary to mention that the maps went through two stages of processing in all the factors, except for the factor of geological map,. The first step was to extract the raw data. The second stage was based on normalization by using natural ruptures. This algorithm reduced the variance within the groups and maximized the variance between them. In the stage of Normalization, the ArcGIS 10.7 reclassification tool was used to create 5 classes for each factor. V1 and V5 were the lowest and highest diversity classes (V), respectively. This formula was classified into 5 categories (very low to very high levels). The focus of the research method of this model was on the spatial analysis of the indicators obtained from Dem 12.5 meters. To evaluate the variability of each parameter, a focal function was applied as a result of the variability. Research findings The results of this study showed that the geodiversity range of the study area decreased from the peaks to the plains, while the areas with low geodiversity values were located in the plains. The lowest diversity (V1) consisted of Quaternary deposits and the highest diversity (V4 and V5) was composed of carbonate formations, intrusive masses, and volcanic formations. Since they were the rarest types of rocks all over the Earth's surface, they were mainly located in the eastern Mishu Mountains. The high values of diversity for the geological factors were related to the erosion-resistant geological substrates, such as volcanic compositions and intrusive masses, while the lowest values of diversity were related to the Quaternary deposits along the valleys and plains. Discussion of Results & ConclusionThe results of the present research showed that the replacement of landforms with geomorphometric parameters and their results in terms of spatial diversity could be a valuable parameter in defining the diversity of physiographic units. Comparison of the results with the geomorphological map of the region provided a validation method. The results showed that the geodiversity range of the study area decreased from the peaks to the plains, while the areas with low geodiversity values were located in the plains. Also, the lowest diversity (V1) consisted of Quaternary deposits and the highest diversity (V4 and V5) consists of carbonate formations, intrusive masses, and volcanic compounds because they were the rarest types of rocks all over the Earth, which were mainly located in the eastern parts of Misho Mountains. The high values of diversity for the geological factors were related to the erosion-resistant geological substrates, such as volcanic compounds and intrusive masses, while the lowest values of diversity were related to the Quaternary deposits along the valleys and plains.
تبلیغات
